Train-heating system



Aug. 21, 1928. 1,681,911

' J. -A. SPENCER TRAIN HEATING SYSTEM Filed Oct. 25, 1924 (IE/72 lfoferzx7- 5 0e7zce7- Ww nib-97a?- Patented Aug. 21, 1928.

UNITED STATES PATENT OFFICE.

JOHN A. SPENCER. OF REVERE, MASSACHUSETTS, ASSIGNOR TO SPENCER THEBMO.

STAT COMPANY, OF CAMBRIDGE, MASSACHUSETTS, A CORPORATION OF MASSACHU-SETTS.

TRAIN-HEATING SYSTEM.

Application filed. October 25,1924. Serial No. 745,831.

This invention relates to heating systems for steam driven railwaytrains and is particularly concerned with devices for enabling the coldfluid, viz, air and water, to

6 be discharged from'the heating pipes within a short period of timethereby quickly to heat a cold train after being made up.

' In steam heating systems for trains in which steam generated by thelocomotive is .0 forced through heating pipes in the several cars, muchtime is consumed before all the cars are heated because the steam isordinarily compelled to drive the cold air and water through the trainto the last car where it is discharged. Usually this results in that thelast car is heated considerably later than the remaining cars, and infact if the steam pressure is insufiicient, the last car is inadequatelyheated.

' Objects of the invention are to overcome the above-objections; toprovide thermostatically controlled devices associated with the heatlngconduits of each car to permit the expulsion of cold fluid therefrom butoperable automatically to prevent the escape of steam; and to provide athermostatic device designed automatically to control the passage offluid at different predetermined temperatures. p One concrete embodimentof the invention is illustrated in the accompanying drawings, in which:I

Fig. 1 is a fragmentary elev-ii-tion of a railway train equipped withthermostatic devices to control the expulsion of cold air from theheatingconduits;

Fig. 2 is an axial section of the thermostatic device with the valveunseated; and Fi 3 is a similar view showing the valve seated.

In the embodiment of the invention illustrated the railway cars A and Bare heated by conduits which aresuitably arranged within the cars andare supplied with steam from the locomotive. The conduit of one car maybe suitably connected to the conduit of the other car, such as by aflexible tube which is adapted readily to be coupled to one or the otherof the conduits. As the steam is turned on from the locomotive it passessuccessively from the front to the rear car through the heating conduitsbut first it is necessary to expel the cold air and possibly waterwithin these conduits before the steam is enabled to enter to providethe necessary heat. In accordance with the inventlon a thermostaticdevice T is associated with the heating conduit of each car, preferablyextending beneath the cars as indicated in Fig. 1. Such device isdesigned to permit the expulsion of the cold. fluid by the incom- 111gsteam but automatically to close when the steam comes in contacttherewith,

The thermostatic device T comprises a casing consisting of an uppersection 1 havmg a projection 2 which is externally threaded forconnecting the device to the heatlng conduit of the car and a lowersection 3 which is screwed into the upper sec-' tion 1 and is providedwith a tubular externally threaded projection 4 in axial align ment withthe projection 2. The interior of the caslng is formed with a cavity 5which may be drained by a manually operable 7 .v'alve 6.

The passage of fluid through the casing is controlled by a valve 7 whichis adapted to cooperate w1th a valve seat 8 threaded into the casingsection 3. The valve 7 is normally held open but upon the entrance ofsteam so The disk 9 is a composite bi-metallic sheet made up of twomaterials, such as iron and brass'having difierent coefiicients ofexpansion so that a change in temperature will cause unequal expansionand contraction of opposite faces of the sheet. The

disk 9 is normally cupped (as by swaging) in such direction that thecomponent part having the higher coefiicient of expansion is on theconcave side. Gonsequentl when the disk is heated it tends to snap tlirto reverse position. The movement of the disk in either direction isdecidedly abrupt section 3 and is pro- 85 ough 10o and owing to therelatively great inherent strength and resilience of the metal the diskwill operate efliciently and reliably for a prolonged period of timewithout attention. The materials and thickness of the component partsand the degree of curvature are so chosen that the disk will snapthrough when heated to the desired temperature (e. g. 210 F.) and willsnap back at a lower temperature (e. g. 180 F.). Suitable materials aresheet brass and nickel steel having thickness of 0.20 and 0.20respectively and suitable cupping for a disk'l in diameter is It shouldbe understood that the present invention is not limited to anyparticular combination of materials having difi'erent thermalcoefficients of expansion but is intended to embrace in its scope anycombination of materials having dissimllar thermal coefficients ofexpansion suflicient to cause the characteristic reversal of curvature.Furthermore, the two materials comprising the composite thermostaticsheet may be secured together in any desired manner by riveting,soldering, brazing or otherwise although it is preferred to unite thematerials comprising the sheet by'welding or similar means to secure asubstantially indivisible sheet.

From the foregoing it will be evident that in one aspect the inventioninvolves a thermostatic device characterized -by portions arranged toreact upon each other with change of temperature to set up stresses themagnitude of which changes upon change of temperature, at least one ofthe portions being formed of different metals or other components havingdifferent coeflicients of expansion, the device reaching a condition ofinstability at a predetermined temper ature by virture of thearrangement of said portions and as a result of the differentialexpansion of the components due to change of temperature, whereupon saidstressesbecomes effective to change abruptly the relative position ofsaid portions.

Closing the outer end of the tubular projection 4 is a cap 12 threadedthereon and provided with a plurality of holes 13 through which fluid isadapted to flow from the casing. Extending through the end of the of thecap 12 is a stem 14 having a head 15, the opposite end of which is inthreaded engagement with the valve 7 so that by manipulating the stem14, the amount of opening and closing of the valve may be controlled. Inorder to lock the stem 14 in the position desired a lock nut 16 therebyto prevent relative movement between the cap and projection 4.

In accordance with theillustrated embodiment the range of flexure orarching ing of the disk 9 in one direction and by adjusting the valveseat relative to the disk or valve 7 the temperature at which the disksnaps through may be varied. This action may be compared to a togglewhich requires less force at the pivoted point to align the togglememberswhen the angle thercbetween is relatively great than when theangle is small. Similarly the arched disk will snap from one position toanother more easily if it is initially flexed a certain amount, or as isthe case with the seat 8 it will resume its initial positionat arelatively higher temperature when the seat 8 is closer to the valvethen when farther away from it. Likewise the stem 14 may be adjusted bythe cap 12 and thus vary the range of flexure in the opposite direction,so that in one sense the stem serves as a stop to limit the flexing orarching of the disk 9 in the opposite direction.

It will be evident that by providing each car with such thermostaticdevice the steam will force cold air and water from the heating conduitsof the train successively and as soon as steam comes in contact with thethermostatic disk the latter will' abruptly snap the valve closed andhold it closed until the steam is turned off when it will again returnthe valve to open position in the same positive and abrupt manner.

An outstanding characteristic of the invention consists in that thepassage of fluid is thermostatically controlled, the thermostatic memberoperating abruptly to unseat and seat the valve at differentpredetermined temperatures. -Preferably the valve is held in openposition until the temperature of the fluid entering the casing rises toa predetermined degree when it automatically operates positively to seatthe valve. The abrupt action of the thermostatic member lnsures thepositive seating and unseating of the valve thereby preventing waste offluid.

valve connected to said thermostat for closing said passageway.

' 2. An escape valve for train heating systems and the like comprising acasing having a threaded nipple at. its upper end for connection to theunder side of a conduit, the casing having a vertical passageway todrain the conduit, a cupped sheet-metal thermostat disposed horizontallyin said casing, and a valve connected to said thermostat for closingsaid tending across said passageway and having a drain openingtherethrough.

3. An escape valve for train heating systems and the like comprising acasing having a vertical passageway to drain the system, the casingbeing formed 111 upper and lower parts, a sheet-metal thermostat clampedbetween said parts and having a drain opening therethrough, and a valveconnected to the thermostat for closing said passageway.

4:. A device of the character described com prising a casing containinga thermostatic sheet cupped to snap abruptly from one shape to anotherupon change of temperature, and an adjusting screw extending through anopening in the casing for adjusting the sheet to snap at differenttemperatures, the casing having an abutment therein cooperating withsaid screw to limit the cupping of the sheet.

5. A device of the character described comprising acasing having anaxial passageway, a temperature responsive device comprising a sheetcupped to snap abruptly from one shape to a different shape, the sheetextending across said passageway and carrying a valve coaxial with thepassageway, and an adjusting screw extending along said passageway andthreading into said valve, the casing having an abutment cooperatingwith said screw to limit the cupping of the sheet.

6. A railway heating system comprising a steam line extendinglongitudinally of a car, a conduit depending from said line with anoutlet beneath the car, a thermostatic sheet extending across saidpassageway and having a drain opening therethrough, and a valveoperatively associated with said sheet coaxial with the conduit, saidsheet being cupped to snap the valve into closed position in response tosteam escaping through said conduit.

7 A railway heating system comprising a steam line extendinglongitudinally of a car, a conduit depending from said line with anoutlet beneath the car, a thermostatic sheet extending across saidpassageway and having a drain opening therethrough, a valve operativelyassociated with said sheetcoaxial with the condu t, said sheet beingcupped to snap the valve into closed position in response to steamescaping through said conduit. and an adjusting screw extendingdownwardly from the valve through said conduit, the conduit having anabutment cooperat ng with said screw to limit the cupping of the sheet.

8. A water drain for steam systems comprising tubular inlet and outletmembers with cupped flanges secured together at their peripheries, a.thermostatic sheet having its periphery confined between said flanges. avalve actuated by the central portion of the sheet, the sheet beingcupped to snap the valve into closed position at a predetermined thesheet through said outlet, the outlet having an abutment cooperatingwith said adjuster to limit the movement of the sheet.

9. A device of the character described comprising two nipples havingflanged bases secured together, a thermostatic sheet having itsperiphery confined between said flanges, a valve seat at the base end ofone of the nipples, and a cooperating valve carried by said sheet, thesheet being deformed to snap abruptly between two positions in one ofwhich the valve is tightly pressed against said seat.

10. In a device of the class described, the combination with a fluidconduit having an outlet, of temperature controlled means to controlsaid outlet, said means including a valve and a perforated thermostaticdisk designed normally to hold said valve open to permit the passage offluid through the disk 12. A device of the class described com-- prisinga casing having a fluid passageway, a valve for controlling saidpassageway, a curved thermostatic sheet for actuating said valve, saidsheet being constructed abruptly to reverse its curvature in onedirection at one end of a predetermined range of temperatures and in theother direction at the other end of said range, and means for limitingthe flexure of said sheet in both directions thereby to control bothlimits of said range.

13. A device of the class described con"- prising a casing having afluid passageway, a valve for controlling said passageway, a curvedthermostatic sheet for actuating said valve, said sheet beingconstructed abruptly to reverse its curvature in one direct on at oneend of a predetermined range of temperatures and in the other directionat the other end of said range, and a stop for restricting the range offlexure of said sheet to control said range of temperature.

14:. A device of the character described compr sing two nipples havingflanged bases secured together, a thermostatic sheet having itsperiphery confined vbetween said flanges, a valve seat at the base endof one temperature, and an adjuster extending from snap abruptly betweentwo positions in one of which the valve is tightly pressed'against saidseat, and an adjustin screw extending along the axis of one of thenipples to vary the temperature range of said sheet, the associatednipple having a cooperating abutment to limit the movement of the sheet.

15. A device of the class described comprising a casing having a fluidpassageway, a valve for controlling said passageway, a curvedthermostatic sheet for actuating said valve, said sheet beingconstructed abruptly to reverse its curvature in one direction at oneend of a predetermined range of temperatures and in the other directionat the other end of said range, and a stop for restricting the range offiexure of said sheet to control said range of temperature, said stopbeing adjustable thereby to vary the flexure of the sheet andaccordingly vary the temperature at which said sheet changes ourvaturein one direction.

16. A device of the class described comprising a casing having a fluidpassageway, a valve for controlling said passageway, a curvedthermostatic sheet for actuating said valve, said sheet beingconstructed abruptly to reverse its curvature in one direction at oneend of a predetermined range of temperatures and in the other directionat the .other end of said range, and stops 'for restricting the range offlexure of said sheet in both directions to control both limits of saidrange of temperature, said stops bein adjustable thereby to varythefiexure oi said sheet and accordingly vary the temperature at which saidsheet changes curvature in both directions.

17. The combination of a valve seat, a bimetallic concavo-convex diskarranged so that changes of temperature cause its center port'on towarp, With snap action, to opposite sides of the plane of its periphery,and a valve on the disk adapted to be seated and unscated through saidwarping movements of the disk, and means whereby, when the (l'sk is inthe valve unseating position, the distance between the center of thedisk and the plane of the periphery thereof may be varied.

I 18. The combination of a valve seat, a bimetallic concavo-convex diskarranged so that changes of temperature cause its center portion towarp, with snap action, to opposite sides of the plane of its periphery,a valve on the disk adapted to be seated and unseated through saidwarping movements of the disk, and an adjusting device to variably limitthe flexing movements of the disk away from the valve seat.

Signed by me at Cambridge, Massachusetts, this second day of October,1924.

- JOHN A. SPENCER.

